Ash vs. Maple

I'm researching how cues are built and what materials are used to make 
them. I'm looking into the woods. It seems like in the U.S. the wood that 
is used primarily to make the shafts and butts (other than all the exotic 
stuff to make the stick look pretty) is Maple. Specifically Sugar Maple. 
However, in the UK, and I think for most snooker cues, the wood used is 
Ash. 

Anyone have any ideas about why this is the case? What are the pros and 
cons of Ash vs Maple? Are there other shock resistant woods that are used 
with some frequency? Thanks.

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